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US5025654A - Pressure standard device - Google Patents

Pressure standard device Download PDF

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Publication number
US5025654A
US5025654A US07/427,139 US42713989A US5025654A US 5025654 A US5025654 A US 5025654A US 42713989 A US42713989 A US 42713989A US 5025654 A US5025654 A US 5025654A
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US
United States
Prior art keywords
pressure
standard device
bearing
piston
conduit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US07/427,139
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English (en)
Inventor
Hans W. Haefner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pfister GmbH
Original Assignee
Pfister GmbH
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Filing date
Publication date
Application filed by Pfister GmbH filed Critical Pfister GmbH
Assigned to PFISTER GMBH, STATZLINGER STRABE 70, D-8900 AUGSBURG, WEST GERMANY reassignment PFISTER GMBH, STATZLINGER STRABE 70, D-8900 AUGSBURG, WEST GERMANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HAEFNER, HANS W.
Application granted granted Critical
Publication of US5025654A publication Critical patent/US5025654A/en
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Expired - Fee Related legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L27/00—Testing or calibrating of apparatus for measuring fluid pressure
    • G01L27/002—Calibrating, i.e. establishing true relation between transducer output value and value to be measured, zeroing, linearising or span error determination
    • G01L27/005—Apparatus for calibrating pressure sensors

Definitions

  • the invention relates to a pressure standard device as set forth in the classifying portion of the claim.
  • the friction between the piston and the cylinder can be further reduced by air or fluid being radially introduced under pressure into the clearance.
  • a further problem arises when measuring pressure in gases when making the transition from the fluid to the gas, in which respect special precautions must be taken if the gas involved is not an inert gas. Even then making the transition from the fluid to the gas gives rise to problems as the position in respect to the height of the piston in the cylinder is not defined. It is therefore necessary to provide stops with relation to excessive movement of the piston both in an upward direction and in a downward direction.
  • German laid-open application (DE-OS) No. 35 14 911 describes another pressure measuring device for measuring a pressure applied to a piston by way of a gaseous medium, wherein the piston is guided in a cylinder in a practically friction-free manner in bearings by virtue of the fact that the bearings are supplied with a fluid under pressure, the piston acting on a force-measuring means.
  • the bearing fluid which escapes into the cylinder chamber containing the gas is removed in a regulated manner in that arrangement.
  • a gas under pressure is supplied to the bearings, while bearing gas which issues into the cylinder chamber can be used for building up the pressure in a conduit which is connected to the cylinder chamber.
  • the GB-A-2056098 discloses a standardized pressure instrument comprising a cylinder and a piston guided therein the height position thereof having to be maintained constant irrespective of a varying loading of the piston in order to prevent a contact to the cylinder.
  • a pressure space is formed being connected to a pressurized fluid via a duct and by loading of the piston with a calibration mass the pressure in the pressure space may be determined.
  • a constant height of zero position, respectively, of the piston is determined by an indicating device and is maintained by supplying fluid to the pressure space.
  • the invention is based on the object of providing a calibration/testing device, the structure of which is considerably simplified, while maintaining a high level of accuracy, in comparison with known devices.
  • a calibration/testing device comprising a housing having a generally cylindrical recess, a piston guided within the recess via hydrostatic/aerostatic bearing means, a pressure chamber formed between the piston and the cylindrical recess, a conduit connected to the pressure chamber for transmitting an exact pressure prevailing in the chamber, and a regulating device for maintaining the piston in a precisely constant position with respect to height independent of varying the load on the piston.
  • the constant position is maintained by the feeding or discharging of fluid to and from the pressure chamber.
  • the pressure within the pressure chamber is defined by loading the piston with calibration weights.
  • the hydrostatic or aerostatic bearing arrangement for the piston in the cylinder is practically friction-less so that there is no need for rotary movement of the piston. It is possible to use a liquid as the bearing fluid, by virtue of the regulated discharge thereof.
  • the arrangement is a particularly simple one when the bearing fluid is used to build up the pressure.
  • the level regulation effect which is used in the invention provides for an exact position in respect of height of the piston in the cylinder so that it does not bear against the end of the cylinder nor can it be displaced upwardly out of its bearings.
  • FIG. 1 is a partial sectional view illustrating the principle of a gas pressure standard device
  • FIG. 2 is a practical embodiment of a gas pressure standard device based on the embodiment shown in FIG. 1;
  • FIG. 3 is a particularly simplified construction of a further embodiment of a gas or liquid pressure standard device.
  • FIG. 1 shows a gas pressure standard device 10 in accordance with a first embodiment of the invention comprising a cylinder 12 which is supported on a base surface and in which a piston 14 is guided in a practically friction-less manner.
  • the piston 14 can be loaded with a calibration weight 46.
  • Formed in the interior of the cylinder 12 is a pressure chamber 30 which is filled with gas, in particular air, and which by way of a conduit 48 applies a pressure p to a piece of equipment which is to be calibrated or tested, for example a pressure measuring cell (see FIGS. 2 and 3).
  • the pressure is essentially determined by the calibration weight 46 and the area of the lower end face 16 of the piston 14.
  • the piston 14 is guided in the cylinder 12 in a practically friction-less manner by way of hydrostatic bearings 20, as are known for example from German laid-open applications (DE-OS) Nos. 31 43 919 or 35 14 911.
  • a bearing liquid for example an oil
  • a pump 24 and a feed conduit 26 A part of the bearing liquid accumulates in pockets 44.
  • bearing liquid also passes into the pressure chamber 30 which is beneath the piston surface 16 and which with the passage of time would be filled up with the bearing liquid, which would lead to the measurement result being adversely affected.
  • the arrangement therefore provides for a controlled return of that bearing liquid from the pressure chamber 30.
  • a conduit 32 leads from the pressure chamber 30 into a closed catch tank 34 which is thus under the same pressure as the pressure chamber 30.
  • the amount of bearing liquid in the tank 34 is now held constant at a predetermined level.
  • the tank has a level-detecting device 36 which can be, for example, in the form of a float, whose position is preferably optically or electrically detected.
  • a regulating device 38 is activated, which opens an emptying valve 42, preferably by way of a motor 40, until the level of bearing liquid has fallen again below the reference level.
  • the bearing liquid flows back into the tank 22, thus providing a closed system in which there is no need for refilling it with bearing liquid.
  • the arrangement provides a high degree of accuracy. It should be noted that the conduit 48 projects somewhat beyond the bottom end of the cylinder 12 so that no bearing liquid can penetrate into the conduit 48.
  • FIG. 2 is a diagrammatic view of an embodiment of a calibration/testing device 50 according to the invention, which approximates to a practical construction.
  • the elements already described with reference to FIG. 1 are denoted by the same reference numerals and will not be described in greater detail in this context.
  • the calibration or testing device shown in FIG. 2 has on the one hand a weight compensating means 54 and on the other hand a position regulating means 70.
  • the compensating means 54 serves in particular to compensate for the weight of the piston 14.
  • the construction which has been selected as an example thereof comprises a two-armed lever 56 which is mounted at a stationary location and which at its one end is pivotally connected to the piston 14 by way of a generally U-shaped member 52 while disposed at its other end is a compensating weight 58 which, in the absence of a calibration weight 46, precisely produces a condition of equilibrium.
  • FIG. 2 also shows the pressure-measuring cell 60 which is to be calibrated or tested and which is subjected with the pressure in the conduit 48.
  • gas in particular air
  • a pump 64 which is driven for example by means of a motor M, until reaching a pressure which can be set by means of the adjusting member 62.
  • the piston 14 Upon an increase in the magnitude of the calibration weights 46, the piston 14 would be urged into the cylinder 12 until finally it comes to bear against the connecting feed portion of the conduit 48.
  • a passive marking or an optical, magnetic or electrical sender 80 which is sensed by means of a sensor 78 which is mounted on a projection at the upper edge of the cylinder 12, in opposite relationship to the sender 80.
  • the sensor 78 is provided with a regulating device which by way of an electric line 76 can actuate a motor 74 in one direction of rotation or the other, depending on whether the piston 14 is too high or too low.
  • the motor 74 moves a control member 72 which supplies gas, in particular air, by way of a pressure conduit 68 to the conduit 48 until the piston 14 has reached its precise position, that is to say a zero position. In that way, upon an alteration in the calibration weight 46, the piston 14 is automatically adjusted again into the correct position.
  • an automatic regulating means 50 is shown in the illustrated embodiment. It is however also possible to provide for positioning adjustment of the piston 14 by manual actuation of the control member 72.
  • FIG. 3 shows a further embodiment of the invention which is of a particularly simple design configuration.
  • This embodiment makes use of the basic concept that the bearing fluid to provide for hydrostatic or aerostatic support for the piston 14 in the cylinder 12 is used at the same time as a pressure medium.
  • the bearing fluid may be a gas or a liquid, gas having the advantage that it does not have an adverse chemical effect on the pressure-measuring cell 60.
  • a given base pressure is applied to the bearing locations by way of the motor-driven pump 24.
  • the pressure chamber 30 is filled with bearing fluid so that finally a corresponding pressure is applied by way of the conduit 48 to the test item, in particular the pressure-measuring cell 60.
  • this embodiment can also use a weight compensating means 54 as shown in FIG. 2.
  • the hydrostatic or aerostatic bearing arrangement according to the invention comprises two spaced-apart bearing rings 20a and 20b, between which there is an annular pocket 44 which is pressure-free, for example by virtue of a bore 45 (see FIG. 3).
  • the outlets of the conduit 26 to the bearing rings 20a and 20b respectively are provided with throttles which retard a feed and return flow of bearing fluid. That means that, in the event of the piston 14 possibly assuming an inclined position, the gap between the piston and the bearing channel becomes asymmetric, in which case a higher pressure occurs at the narrower location and a lower pressure occurs at the wider location, thus moving the piston back into a vertical position.
  • each bearing channel 20a and 20b may again be divided into three mutually parallel individual channels or grooves which are respectively fed by way of throttles.

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  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)
  • Rotary Presses (AREA)
  • Inking, Control Or Cleaning Of Printing Machines (AREA)
US07/427,139 1987-05-08 1988-05-07 Pressure standard device Expired - Fee Related US5025654A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3715450 1987-05-08
DE19873715450 DE3715450A1 (de) 1987-05-08 1987-05-08 Drucknormal

Publications (1)

Publication Number Publication Date
US5025654A true US5025654A (en) 1991-06-25

Family

ID=6327138

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/427,139 Expired - Fee Related US5025654A (en) 1987-05-08 1988-05-07 Pressure standard device

Country Status (5)

Country Link
US (1) US5025654A (de)
EP (1) EP0360810B1 (de)
JP (1) JPH02504068A (de)
DE (2) DE3715450A1 (de)
WO (1) WO1988008966A1 (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5331838A (en) * 1992-12-03 1994-07-26 Delajoud Pierre R Dead weight piston drive and control system
US6701791B2 (en) * 2001-11-16 2004-03-09 Calamerica Corp. Modular piston gauge method and apparatus
US7146843B1 (en) * 2005-12-06 2006-12-12 Dietz Henry G Extreme low air pressure deadweight tester
KR100806959B1 (ko) 2006-08-31 2008-02-22 한국표준과학연구원 피스톤이 회전하지 않는 분동식 압력계
CN102175389A (zh) * 2011-02-21 2011-09-07 吉林大学 滚动摩擦活塞式压力计
US11118994B2 (en) * 2016-07-29 2021-09-14 Kunshan Innovation Testing Instruments Co., Ltd. Precision detection device for force standard machine, force value comparison machine and precision detection method for force standard machine
CN113567043A (zh) * 2021-08-04 2021-10-29 广西壮族自治区计量检测研究院 一种具有修正高度差功能的隔离器

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0403677B1 (de) * 1989-06-22 1993-04-14 A. M. Erichsen Gmbh Kraftnormal-Messeinrichtung mit hydraulischer Kraftübersetzung
NL2010455C2 (en) 2013-03-14 2014-09-16 Glind Metrology B V Hydraulic pressure calibrator and calibration method.
DE102013215351A1 (de) * 2013-08-05 2015-02-05 Wika Alexander Wiegand Se & Co. Kg Verfahren zur bereitstellung von referenzdrücken

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796229A (en) * 1952-08-15 1957-06-18 Donald H Newhall Pressure cylinder unit and method
US3407644A (en) * 1965-06-15 1968-10-29 Kobe Steel Ltd Method and apparatus for generating standard pressure
US3633402A (en) * 1970-08-31 1972-01-11 James R Miller Deadweight tester weights
DE2323019A1 (de) * 1973-05-08 1974-11-28 Friedrich Dr Phil Ehrler Vorrichtung zum vorgeben, messen und regeln von druecken
GB2056098A (en) * 1979-08-04 1981-03-11 Fogarasy A A Hydraulic force cell
SU845030A2 (ru) * 1979-08-10 1981-07-07 Предприятие П/Я Р-6521 Устройство дл автоматическогозАдАНи и пОддЕРжАНи дАВлЕНи
SU972288A1 (ru) * 1981-04-03 1982-11-07 Предприятие П/Я М-5539 Устройство дл калибровки датчиков импульсного давлени
SU1008633A1 (ru) * 1981-06-04 1983-03-30 Всесоюзный Научно-Исследовательский Институт Метрологической Службы Грузопоршневой задатчик давлени
US4491016A (en) * 1981-11-05 1985-01-01 Pfister Gmbh Method and apparatus for measuring the pressure of a fluid
GB2176007A (en) * 1985-06-07 1986-12-10 Labofina Sa Dynamic calibration method and system for pressure measurement circuits
US4711127A (en) * 1985-04-25 1987-12-08 Pfister Gmbh Method and apparatus for measuring the pressure of a fluid
US4798094A (en) * 1988-01-11 1989-01-17 The Unites States Of America As Represented By The Secretary Of The Army Hydrostatic primary force standard

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2420746A1 (fr) * 1978-03-24 1979-10-19 Vnii Metrologi Sluzby Dispositif automatique pour controler des appareils de mesure de pression

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2796229A (en) * 1952-08-15 1957-06-18 Donald H Newhall Pressure cylinder unit and method
US3407644A (en) * 1965-06-15 1968-10-29 Kobe Steel Ltd Method and apparatus for generating standard pressure
US3633402A (en) * 1970-08-31 1972-01-11 James R Miller Deadweight tester weights
DE2323019A1 (de) * 1973-05-08 1974-11-28 Friedrich Dr Phil Ehrler Vorrichtung zum vorgeben, messen und regeln von druecken
GB2056098A (en) * 1979-08-04 1981-03-11 Fogarasy A A Hydraulic force cell
SU845030A2 (ru) * 1979-08-10 1981-07-07 Предприятие П/Я Р-6521 Устройство дл автоматическогозАдАНи и пОддЕРжАНи дАВлЕНи
SU972288A1 (ru) * 1981-04-03 1982-11-07 Предприятие П/Я М-5539 Устройство дл калибровки датчиков импульсного давлени
SU1008633A1 (ru) * 1981-06-04 1983-03-30 Всесоюзный Научно-Исследовательский Институт Метрологической Службы Грузопоршневой задатчик давлени
US4491016A (en) * 1981-11-05 1985-01-01 Pfister Gmbh Method and apparatus for measuring the pressure of a fluid
US4711127A (en) * 1985-04-25 1987-12-08 Pfister Gmbh Method and apparatus for measuring the pressure of a fluid
GB2176007A (en) * 1985-06-07 1986-12-10 Labofina Sa Dynamic calibration method and system for pressure measurement circuits
US4798094A (en) * 1988-01-11 1989-01-17 The Unites States Of America As Represented By The Secretary Of The Army Hydrostatic primary force standard

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Messen, Steuern und Regeln in der Chemischen Technik", pp. 112-117 (1980).
Messen, Steuern und Regeln in der Chemischen Technik , pp. 112 117 (1980). *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5331838A (en) * 1992-12-03 1994-07-26 Delajoud Pierre R Dead weight piston drive and control system
US6701791B2 (en) * 2001-11-16 2004-03-09 Calamerica Corp. Modular piston gauge method and apparatus
US7146843B1 (en) * 2005-12-06 2006-12-12 Dietz Henry G Extreme low air pressure deadweight tester
KR100806959B1 (ko) 2006-08-31 2008-02-22 한국표준과학연구원 피스톤이 회전하지 않는 분동식 압력계
CN102175389A (zh) * 2011-02-21 2011-09-07 吉林大学 滚动摩擦活塞式压力计
US11118994B2 (en) * 2016-07-29 2021-09-14 Kunshan Innovation Testing Instruments Co., Ltd. Precision detection device for force standard machine, force value comparison machine and precision detection method for force standard machine
CN113567043A (zh) * 2021-08-04 2021-10-29 广西壮族自治区计量检测研究院 一种具有修正高度差功能的隔离器
CN113567043B (zh) * 2021-08-04 2023-03-14 广西壮族自治区计量检测研究院 一种具有修正高度差功能的隔离器

Also Published As

Publication number Publication date
DE3873539D1 (de) 1992-09-10
DE3715450A1 (de) 1988-11-24
JPH02504068A (ja) 1990-11-22
WO1988008966A1 (en) 1988-11-17
EP0360810B1 (de) 1992-08-05
EP0360810A1 (de) 1990-04-04

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Legal Events

Date Code Title Description
AS Assignment

Owner name: PFISTER GMBH, STATZLINGER STRABE 70, D-8900 AUGSBU

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HAEFNER, HANS W.;REEL/FRAME:005185/0219

Effective date: 19891004

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19950628

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362